I found these tornado machine plans on the internet via Digg. Once i read it, i said to myself "I HAVE to build one". However, this was a challenge as I barely have any experience with cutting wood, let alone heating plexiglass.
Anyways, long story short, suprisingly i finished building it in 16 man-hours. Here is a video and some pics. The video has some type of chirping sound. It's a side effect i'm guessing of the digital camera that i used to record the video ;-)
It was real fun at first, but now it just lays in my room collecting dust. One day a co-worker at college was having a presentation and field trip for 60 14-year olds. I thought, why don't i bring the tornado machine? I'm sure kids would love this thing! And guess what!? They had alot of fun with it! I think i'll just let schools borrow this thing to teach kids about tornados.